Thousands of angry and distraught Russians have rallied in a Siberian city to demand a full probe into a shopping centre fire that killed at least 64 people, many of them children.

President Vladimir Putin visited the city and blamed the deaths on “a criminal negligence, sloppiness” as he laid flowers in tribute to the victims. He did not meet with the protesters.

The blaze engulfed the Winter Cherry mall in Kemerovo on Sunday, the first weekend of the school holidays, trapping dozens of parents and children inside.

Eyewitnesses reported that fire alarms were silent and many doors were locked. Some of the victims were children who died in a locked movie theatre.

The residents rallied outside the regional government building in Kemerovo for hours, with many of the protesters taking the stage to accuse the authorities of hiding the real scale of the disaster.

People hold portraits of relatives killed in a fire in Russia (Sergei Gavrilenko/AP)

The impromptu protest underscored the residents’ frustration with the official response to the tragedy: the local governor has not visited the site of the fire or met with the relatives, and Mr Putin has not announced a period of national mourning.

Mr Putin flew to Kemerovo earlier on Tuesday and visited the makeshift memorial to the victims outside the shopping centre. The footage released by his press office showed the president laying flowers on a deserted plaza with his security detail guarding the perimeter.

“How could this possibly happen? What’s the reason?” Mr Putin said at a meeting with the taskforce dealing with the fire, according to comments distributed by his press office.

Investigators said emergency exits were blocked and a security guard turned off the public announcement system when he received a call about the blaze.

Alexander Bastrykin, chief of the Investigative Committee, told Mr Putin during a meeting in Kemerovo that the fire alarm had not been operational for two weeks and the security guard was detained but they still had no “reasonable” explanation for his actions.

Deputy governor Vladimir Chernov, the only top official who showed up at the rally, dismissed the unconfirmed reports of hundreds of deaths as rumours and said he was ready to resign if people want him to.